基于时间分辨荧光光谱法同时测定己酸乙酯与乙酸乙酯

The Fluorescnece Lifetime and Quantum Chemistry Calculation of Ethyl Caproate and Ethyl Acetate

提出了一种基于时间分辨荧光光谱分析法同时测定己酸乙酯和乙酸乙酯混合液中各组分浓度的方法。实验测得两种单体物质的荧光发射光谱重叠度达到78%。对于荧光发射光谱重叠度很高的物质使用普通荧光方法结合算法也很难进行定量分析。而通过量子化学计算结果,对两种单体的分子结构分析,得到己酸乙酯的荧光寿命长于乙酸乙酯。通过时间分辨荧光光谱测量得到己酸乙酯和乙酸乙酯的荧光寿命分别为1.0和5.3ns。两种物质的荧光发射光谱重叠严重,但是其荧光衰减曲线有明显的差别,所以提出使用时间分辨荧光光谱法对两种物质进行定量分析。通过分析两种物质不同体积比下的荧光衰减曲线的变化趋势,建立两种物质体积比的预测模型,并对其进行检验。实验结果表明:该方法能够实现混合溶液中各组分体积比的测量,其测量的平均残差控制在1%以内,具有一定的实用价值。

This paper presents a method for quantitative analysis of the volume ratios of various substances in mixtures using fluorescence lifetime.The two kinds of fluorescent materials,ethyl caproate and ethyl acetate,were selected as standard samples.The spectral overlap of thyl caproate and ethyl acetate was 78%.For materials with high overlap of fluorescence emission spectra,it was difficult to make quantitative analysis with the combination of ordinary fluorescence with algorithm,because their overlap of fluorescence emission spectra was serious.The molecular structure of the two substances was quantified by quantum chemistry.The life time of ethyl caproate was 1.0 ns and the ethyl acetate was 5.3 ns.However,their fluorescence decay curves were obviously different.Therefore,this paper did quantitative analysis to them through time resolved fluorescence spectrometry.By analyzing the change trend of the fluorescence lifetime curve of the two substances at different volume ratios,aprediction model of fluorescence lifetime and volume ratio of two substances was established and tested.The experimental results showed that the method can achieve the measurement of the volume ratio of the mixed solution,and the mean residuals were controlled within 1%,which had certain practical value.